, 3 min read
I sometimes teach a C programming language course. I use the following simple exercises for the students to solve on their own. Most solutions are no longer than 10-20 lines of C code. Exercising simple loop and printf(): Print a table of square root values for arguments 1 to 30. Exercising…
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In three earlier posts I showed the development of this blog. Statistics of this Blog: 2.600 Views, 78 Countries, 20 Comments, February 2014 Statistics of this Blog: 1.000 Views, 60 Countries, 10 Likes, October 2013 My Blog Statistics by Country, September 2013 Today I can announce that I crossed…
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This workshop is planned for 14-15 July 2014 in Jena, Germany. The workshop is organized by Bernd Brügmann (University Jena), Xing Cai (Simula and University Oslo), Gundolf Haase (University Graz), and Gerhard Zumbusch (Chair, University Jena). The last workshop from 2011 had two high-profile…
, 2 min read
One simple way to get rid of the very short timeout in shell access to OpenShift is to unset the TMOUT environment variable: unset TMOUT Before I knew that I used an Expect script. Below Expect script defeats the annoying timeout by sending some text every 60 seconds. #!/usr/bin/expect # Defeat…
, 4 min read
I recently installed Ubuntu 14.04 (Trusty) on my new 2TB hard drive. I do not use the desktop variant of Ubuntu because I think it is too bloated. Rather I specifically install packages as needed. Below is a list of packages I install after the server edition. jpilot, of course, see my posts…
, 4 min read
Probably I am a little bit old-fashioned, but I still use J-Pilot on my PC and my Tungsten T5 and sync them. It mostly serves as a kind of backup so I have my valuable address and datebook data on separate media. So in case my PC gets inaccessible then I have my data on this device at least. These…
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Assume you want to download just the music of below video on Youtube, so you can listen to the music on your phone, while you are on the road. Here are the necessary steps on the command line: youtube-dl www.youtube.com/watch?v=aHjpOzsQ9YI mv Crystallize\ -\ Lindsey\ Stirling\ \(Dubstep\ Violin\…
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A post in Phoronix: "Cryogenic" Linux Kernel Drops Power Use shed light on a Linux kernel module improving power consumption. This module was written as part of a master thesis in computer science at TUM (Technical University of Munich) by Alejandra Morales Ruiz. The thesis is well…
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Wikipedia contains an article on d'Hondt's method for calculating the number of seats given the number of votes for each party. I wrote a short Perl program for its calculation including the case when d'Hondt's method by its design leads to drawing the lots. Its input contains a list of party names…
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Very nice article on http://pilotseye.tv/ Added on 20-Mar-2014: Original blog post, which was reblogged here, apparently has been deleted. So I put a video from PilotsEYE here: -- -- -- Quote -- -- -- I have always been interested in flying and aviation. I recently found an…
, 2 min read
In two previous posts My Blog Statistics by Country and Statistics of this Blog: 1.000 Views, 60 Countries, 10 Likes I showed the statistics of this blog in September and October last year. The last few weeks I was quite heavily loaded with work, so I couldn't announce that I broke the 2.000…
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I found a marvelous way to run jobs on certain business days via cron. The solution was depicted in Scheduling Cron Jobs on Business Days and it was written by a user named rdcwayx. The idea is to use the output of cal and some Awk or Perl string-trickery. The output of cal looks like this …
, 3 min read
Cisco provides a report on computer security which contains a number of key findings: Java comprises 91% of all web exploits. 99% of mobile malware targets Android. Java is the exploit that criminals choose first, since it delivers the best return on investment. In the aftermath of the Boston…
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Today I noticed the following error on Youtube, which seems to be quite rare. Maybe some trained monkey comes by and can make use of below gibberish. 500 Internal Server Error Sorry, something went wrong. A team of highly trained monkeys has been dispatched to deal with this situation. If you see…
, 1 min read
Unfortunately Google gets quite draconian to users: When using Google Chrome to surf a web page with a certificate problem, you simply cannot view the website. There is no dialog, where you can say: It's o.k., I accept the risk. This behaviour occurs at least with versions 31.0.1650.63 and…
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Sometimes you have to create applications in an environment where you are not able to su to root, or use sudo. Nevertheless you are working with two or more user IDs to make your application work. For example, your business application is running under user ID 1555 (let's call this user u1555),…
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In continuation of Working with System V IPC queues a month ago this post will show how to access IPC queues with Perl and PHP. A typical scenario is that a web application wants an external application to process data coming from the web application. In that scenario a lot of messages/tasks from…
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I own a desktop PC with an AMD octacore FX 8120 and a NVidia GTX 560 graphic card running GPUGrid. What is the power consumption in Watts over time? I ran ( while true; do powerconsum ; sleep 2; done ) & with below script powerconsum reading data from sensors: #!/usr/bin/perl -W use…
, 3 min read
A couple of times I had to conduct effort estimations which contained a number of repetitive tasks. The question was, how long does it take to finish all these tasks. For example, I had to provide estimates how many days it would cost to program an interface between one system interfacing to a…
, 2 min read
Android application programs are usually written in the Java programming language. Java source code is compiled to bytecode, which is then interpreted by the Java virtual machine. Current virtual machines (VM for short) use two tricks to improve performance: compile bytecode to machine code during…